As a passive light-emitting flat-panel display device, a thin film transistor-liquid crystal display (TFT-LCD) needs to be cooperate with a backlight source so as to operate normally, because liquid crystal molecules are incapable of emitting light. White light from the backlight source passes through a first substrate (e.g., an array substrate), a liquid crystal layer and a second substrate (e.g., a color filter substrate) sequentially, so as to achieve a full-color display and grayscale brightness. However, a conventional structure is relatively complex, and thereby the light-emitting efficiency is relatively low.